Tires having continuous ribs oriented parallel to the longitudinal direction of the tread are commonly used on e.g., commercial vehicles. A common placement of such designs on commercial vehicles can include the steer tire positions on a commercial truck. Ribs constructed in such a manner can provide rolling resistance performance that is much better than e.g., tread patterns having blocks or non-continuous ribs. Improved rolling resistance performance can provide better fuel efficiency, a particularly desirable feature in view of increasing fuel costs.
One challenge with ribs oriented parallel to the longitudinal direction, however, is relatively poor traction performance. This characteristic results from e.g., the lack of transverse edges that provide grip as the tire rolls over the road surface. Thus, tires having such rib construction are typically not used on e.g., the drive tires of commercial vehicles. Instead, as stated above, such tires are commonly placed in the steer positions where a high level of longitudinal traction is not required.
Additionally, such longitudinally oriented ribs are subject to irregular wear. As used herein, “irregular wear” means that the wearing of the ribs is not uniform from rib to rib. Such irregular wear can e.g., shorten the life of the tread and create unwanted vibrations as the tire rolls across the road surface. Although siping can be added to reduce such irregular wear, such can also adversely affect rolling resistance performance.
Accordingly, a ribbed tire that provides desired rolling resistance and traction performance would be useful. More particularly, a tire that can provide the rolling resistance performance of a continuous rib while also providing needed traction performance would be beneficial. Such a tire that can also be provided with features for preventing or reducing irregular wear would also be very useful.